FAIR VALUES OF FINANCIAL INSTRUMENTS (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Assets:
Secured loans receivable and investments, net	$ 400,889	$ 635,002
Unsecured loans receivable, net	38,238	62,118
Available-for-sale Securities	21,200
Liabilities:
Redeemable OP unitholder interests	111,700	114,900
Carrying Amount
Assets:
Cash and cash equivalents	54,672	67,908
Secured loans receivable and investments, net	379,727	635,002
Unsecured loans receivable, net	38,238	62,118
Marketable Securities	21,162	5,400
Liabilities:
Senior notes payable and other debt, gross	9,359,018	8,186,315
Derivative instruments and other liabilities	16,360	45,966
Redeemable OP unitholder interests	111,697	114,933
Fair Value
Assets:
Cash and cash equivalents	54,672	67,908
Secured loans receivable and investments, net	388,780	636,714
Unsecured loans receivable, net	40,762	65,146
Available-for-sale Securities	21,162	5,400
Liabilities:
Senior notes payable and other debt, gross	9,471,240	8,600,450
Derivative instruments and other liabilities	16,360	45,966
Redeemable OP unitholder interests	$ 111,697	$ 114,933